In the new movie Dealin’ with Idiots—opening in Chicago July 12, New York on July 17, L.A. on July 19 and nationwide on video-on-demand—comedian Jeff Garlin takes on the complicated politics of Little League baseball. Garlin, who also directed, stars — alongside Fred Willard and Gina Gershon — as a comedian who decides to mine the parents on his son’s baseball team for movie-making material. That’s not so far from the way Dealin’ with Idiots came to be: though Garlin’s own baseball-playing son no longer does Little League (and his other son played soccer instead of baseball), the comedian attended his friends’ kids games and saw what was going on. And though Dealin’ with Idiots was completely improvised, he says the crazy antics of over-involved parents are a fact of modern kids’ sports.

So, now that he’s made a whole feature film about what not to do as a sports parent, what are his tips for attending your child’s Little League game without being an idiot?

As far as other advice goes, Garlin is reluctant to play coach. “I’m an expert on nothing except napping,” he says. “I know nothing.” But he does say that, while he attended his son’s Little League games because they required parental chauffeuring, the other etiquette he learned was to sit quietly. (The absolute worst thing: running on the field.)

One thing he says he’s sure about: being a parent is a hard job but one that’s ripe for comedy.

“I have no idea [why parents act idiotically]. That’s after going to a million games and making a movie all about it. If I was a sociologist I might have a different take,” he says. “I have a million thoughts as to why—but none that are even remotely insightful.”